Remove an object from List of dynamic object

Question

//Data is IList<ExpandoObject>
var result = (from dynamic item in Data
              where item.id== "123"
              select item).FirstOrDefault();

Want to achieve below feature but it is erroring out by saying remove not available for dynamic objects.

Data.Remove(result);

Let me know if any suggestions. thanks

Have you tried casting `result` back to `ExpandoObject` when you pass it? — madreflection, Feb 19 '20 at 21:19
Does this answer your question? [Add dynamic to IList fails](https://stackoverflow.com/questions/51240596/add-dynamic-to-ilistt-fails) — Andrew Savinykh, Feb 20 '20 at 06:24

score 3 · Answer 1 · answered Feb 19 '20 at 21:43

3

Error: remove not available for dynamic objects

base on Microsoft's docs, The Remove method of IList<T> accepts a parameter with the type of T:

ICollection<T>.Remove(T)

In your example, T is an ExpandoObject, so it means in the Remove method you should pass a parameter with the type of ExpandoObject but you didn't and you are passing a parameter with the type of dynamic. Therefore you facing this error

for resolving this you have two way:

1) Use explicit type instead of var:

ExpandoObject result = ...

2) cast the result when you are passing it to Remove:

Data.Remove((ExpandoObject) result)

I think with doing one of these ways, your problem will resolve. good luck.

answered Feb 19 '20 at 21:43

Hamed Moghadasi

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The LINQ expression is casting `ExpandoObject` to `dynamic`, so as part of declaring `result` as `ExpandoObject` (#1), you would have to cast the result of the LINQ expression back to `ExpandoObject`. #2 is probably easier to understand at a glance and is correct without modification. – madreflection Feb 19 '20 at 21:50
_"so it means in the Remove method you should pass a parameter with the type of ExpandoObject but you didn't and you are passing a parameter with the type of dynamic"_ I'm not sure this is strictly accurate. The point of `dynamic` is exactly so that it can be passed instead of anything and that it gets resolved at run time. Note, that this (OP) works perfectly in .net 3.0, so I suspect that this is just a framework bug that got fixed in .net core. – Andrew Savinykh Feb 20 '20 at 00:28
See my comment to the OP for the original bug. – Andrew Savinykh Feb 20 '20 at 06:26

Remove an object from List of dynamic object

1 Answers1